Automatic train control.



W. V. TURNER.

AUTOMATIC TRAIN CONTROL. APPLICATION FILED APR. 1. 1916.

muhuk Patented Oct. 23, 1917.

lrmlllhlk INVENTOH e e m omitt n ite etir ment;a sets ewe meHoUsE AIR BRAKE COMPANY, 'QFiWILMERDIN PENNSYLVANIAfA cor isonema or P NNSYLVANIA,

*AUToMATftc Tie-naturism.

specification be rater; Patent, Tgttentdoet, 23, 1917,

ApplicationfiledApril-l,1916. 'S'erialNozSSflS l. Y

To all whom it may concern: 7

Be it known that I, WALTER V. TURNER, a citizen of the United States, residing at \Vilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented new and useful Improvements in Automatic Train Controls,' of which the following-is a specification. a p

This invention relatesto automatic train control systems, and more particularly to the type employing'electric track circuits. It is highly desirable where electriotrain control systems are employechthat the controlling track circuit for same'be arranged on theso-ca'lled normally closed circuit principle, sothat if'the circuit is broken from any cause or if there is a failure of current, the train apparatus will be operated in the samemanner asif thetrack circuit were opened automatically when a danger' condition exists. a I i 7 ''It has'been proposed to employ continuous conductors along the track in whiclfthe circuit is normally closed but this requires considerable current, insulation-of the rails or conductors,-and might interfere with the operation of the wellknow'n automatic ielectric block signal system where such" a system is installed. 7 a

The principal object of'niy invention is to provide an electric-train "control system operating on normally closed ci'rcuitJ in which'short' conductor sections can 'beemployed. 111 the accornpainyingfclra'wing, Figure 1 is' aview, mainly'in se'ction,"of'a train control" app aratus embodying my invention and Figr2 a diagrammatic viewof the track circuit"-arrangernent for controlling the"train control apparatus. a

According to m invention at the desired block intervals along the track, there :is' provided a rail section 1, as shown in Ei gxl, which is insulated from the groundiand is connected to'a source of-icurrent- Qrvvhich is normally grounded at 3 throughthe' normally closed switch 4.

- The train is equipped; as shown' in Fig; 2 of the drawing; with a downwardly proj ecting shoe 5*which is adapted to'e'ngage-the successive conductorsections 1 asthetrain' moves: along the track. Theshoe 5 is arranged to he moved upwardly -by engagement 'Withva rail secti-on l andvat the same time electric contact is made for completing a' circuit fromthe: rail through a magnet 6 to aground 7. q- The verticalmoveinentof the shoei5*is adapted toactuate-a"valve '8 for effecting the operation of a-valvemechanisrn which inturn operates to cause an" application'- of the brakes, but'if the rail'l isfienergi'zed, the 'inagnet G-Will also he energized and, as will be explained; thisrprevents the operation of the brake applying'valve'arlechama a The brake controlling valve mechanism may comprise"acasing't) :havingapiston chamber 19 containiriga piston 11 and a Valve: chamber =12 containing a sli'deva'lve 13. ':Tl16 tva-lve chamber i2 isconnected to a source of fiuid under pressure; preferably the main reservoir 14 and is adapted upon operation to vent fluid from the "brake pipe 15 to effect an applicationof'the brakes in the usual-Inannen- V i A: passage I 16 leads from piston chamber 10 to a difiefrentiahpiston device havingpis- 7 ton heads l'i' -andl 18,- and thep'iston chamber at'the :outer-f'acehf piston-head 18 is connected by-"a-passage 19 to adouble'beat valve device-having valves 20 and'33 which is "cont'rolledby' the-magnet 6.: i

' 'The shoe5 is secured toa' vertically nio-v- I able plunger E22 'n'iou-iited' in "a casting :21 and the plunger is providedwitfh acain portion '23 adapted toengage: the roller 24: of "a reckerarm25. i

The valve 8 is'providedwitha steinf'26 adapted to be" operated the rocker arm atmosphere.

%Pipe 27 is connected to a *branchedf'pa'ssage-28,.having one'loran'ch controlled by the piston head 17 and having the otherfbran'oh lea-'dinQ tothe pistonchamher at the face of piston head 17; g In operation; fluidiunder pressure is supplied from main reservoir" 14 through pipe 29 to valve chamber 12 and flowsthrough port 30'in'piston ll'to pistQn'chamber lO. Fluid alsofiovvsl:'rorn piston chamber-10 I through passage '16 and annularvpassa-ge 31 to passage. 28 and the rice to the face I of pis- A passage 32 leads-afrom valve chamber 12 to" chamber" 34: containing "valve '20 and also to the piston chamber containing pis ervoir 39 with an exhaust port 40 and fluid.

is supplied from the main reservoir 14 through valve chamber 12, passage41 and pipe 42 to the usual feed valve device of brake valve 43, so that the supply of fluid for maintaining the brake pipe pressure in the running position of the brake valve is controlled by the application valve device.

The stem connecting the double beat valves 20 and 33 has a piston fit in the inclosing bushing, but is provided with a small port 44 which connects passage 19 with exhaust port 45 when valve 33 is open, so that the outer face of piston 18 is normally at atmospheric pressure.

When the shoe 5 passes over a contact section 1, ifswitch 4 is opened on account of a danger condition, or if the track circuit is broken or current fails, the magnet 6 will not be energized and the differential piston device will therefore remain in its normal position, but the shoe 5 will be raised by engagement with the contact section 1 so that the valve 8 is lifted from its seat and fluid is vented from pipe 27.

Since pipe 27 is connected through passage 28, annular passage 31 and passage 16 with piston chamber 10, fluid will be vented from said chamber and the piston 10 then operates the slide valve 13 so as to connect brake pipe 15 through a cavity 46 with exhaust port 40. Fluid is therefore vented from the brake pipe to eflect an application of the brakes in the usual manner. At the same time, the slide valve 13 blanks passage 41, so that the supply of fiuid from the main reservoir to the brake valve is out off and the brake valve is thus prevented from supplying fluid to the brake pipe.

.Cavity 37 in slide valve 13 also connects passage 38 with a passage 47, so that after the vent valve 8 closes when the shoe 5 leaves the contact section 1, the piston 11 will be held in application position for apredetermined period of time, until thetimin reservoir 39 has. been charged with fluid under pressure, by flow from the valve chamber 12 through port 30, to a pressure substantially equal to that in valve chamber 12, when the spring 48 will return piston 11 and slide valve 13 to release position.

When the slide valve 13 is shifted torelease position, the feed valve passage 41 is again connected to the valve chamber 12 and the main reservoir 14, so that the brake valve 43 operates to recharge the brake pipe and thus efiect the automatic release ofthe brakes, i,

'of fluid from valve chamber 12 through passage 32 to passage 19, so that the outer face of piston head 18 is subjected to fluid under-pressure vAt the same time, fluid is vented from the face of piston head 17 through pipe 27 and vent valve 8, so that the differential piston device is shifted to cut ofi' communication from the passage 28 to passage 16. It will thus be seenthat while the vent valve 8 is opened as before by the vertical movement of shoe 5 in passing onto the contact section 1, fluid will not be vented from piston chamber 10, so that in this case the brakes will not be applied, since the application piston will remain in release position. The movement of the diflerential piston is assisted by the venting of fluid from the face of piston head 1'? through passage 28 and pipe 27. p

In order to prevent possible movement of the differential piston device to normal po sition before the contact shoe has passed off the contact section 1, the trip valve timing reservoir 36 has been provided, which is connected through pipe 35 with the chamber r at the outer face of plston head 18 when said piston head ismoved to its inner position. Since this reservoir is charged with fluid from the main reservoir, .as previously de scribed, the differential piston will be maintained in its cutout position for a predetermined periodof time, depending upon the rate at which thereservoir is exhausted through passage 19 and the port 44 when the valve 33 is returned to its open position upon deenergization of magnet x I It will now be apparent that 'with the present construction, the amount of current required for operation is reduced to a minimum, since only short contact sectionsiare employed, -while by providing normally closed track circuits, any failure,- will be on the side of safety. It will always be noted thatthe system does not require a source of current on the train, which has obvious, ad-

vantages in the way of reducing the cost of maintenance and in simplifying the train apparatus. Y

Having now described my invention, what I claim as new and desire to secure by Letters Patent is x 7 V.

1. In an automatic train control system, the combination with a brake pipe, a reduction in pressure in which is adapted to eflect an application of the brakes and valve device for venting fluidfrom the brake pipe, ofa valve adapted to. be operated inechani cally by means along the track for varying the fluid pressure on .said valvedevi'ce, a

valve mechanism for controlling communication from said valve to said valve device, and means responsive to an electrical condition along the track for eflecting the operation of said valve mechanism to cut oil said communication.

2. In an automatic train control system,

.the combination With a valve device for efnication between said valve and said valve device.

3. In an automatic train'control system, the combination with a valve device operated'by a variation in fluid pressure for effooting an application of the brakes, of a mechanically responsive means for varying the fluid pressure on said valve device, a piston device for controlling communication through which the fluid pressure is varied, and clectro-responsive means for. supplying fluid to one side and for venting fluid from the other side of said piston device to operate the same and cut off said communication.

4:. In an automatic train control system, the combination with a valve device operated by a variation in fluid pressure for eflecting an application of the brakes, of a mechanically responsive means for varying the fluid pressure on said valve device, a piston device for controlling communication through Which the fluid pressure is varied, electro-responsive means for supplying fluid to one side and for venting fluid from the other side of said piston device to operate the same and cut ofi said communication, and means for maintaining said piston device in its out off position for a predetermined period of time.

In testimony whereof I have hereunto set my hand.

WALTER V. TURNER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. 0. 

